306 results about "Intra mode" patented technology

An example device for decoding video data includes a memory configured to store video data; and a processing system comprising one or more processors implemented in circuitry, the processing system being configured to: generate a prediction block for a current block of video data using a neural network; determine an equivalent intra mode for the prediction block from a set of available intra-prediction modes using decoder-side intra mode derivation (DIMD), the equivalent intra mode representing one of the intra-prediction modes that would generate an intra-prediction block that would best match the prediction block generated using the neural network; decode a residual block for the current block of the video data based on the equivalent intra mode; and combine the prediction block with the residual block to decode the current block of the video data.

A video encoder and video decoder may determine to code a block of video data using a non-directional intra mode. The video encoder and video decoder may determine a secondary transform from a secondary transform set for the block, and perform a transform process on the block of video data using the secondary transform. For non-directional intra prediction modes, the secondary transform set has a first number of transform kernels that is less than a second number of transform kernels in the secondary transform set for other blocks coded using a directional intra mode.

A method and apparatus for generating an extended MPM (Most Probable Modes) list by adding the target DIMD candidate and said at least one neighbouring mode of the target DIMD candidate to an initial MPM list. A target DIMD candidate is determined for the current block based on a DIMD process using statistics or histogram of angle field derived from a template of the current block. At least one neighbouring mode of the target DIMD candidate is generated by adding an offset to a corresponding mode number of the target DIMD candidate, and wherein the offset corresponds to a non-zero integer. An extended MPM (Most Probable Modes) list is generated by adding the target DIMD candidate and said at least one neighbouring mode of the target DIMD candidate to an initial MPM list. The current block is encoded or decoded using information comprising the extended MPM list.

A method for implicitly deriving region-based intra-prediction is provided. A video coder receives data for a block of pixels to be encoded or decoded as a current block of a current picture of a video. The video coder identifies an above template region and a left template region of the current block among already-reconstructed pixels of the current picture. The video coder derives a first intra-prediction mode based on the above template region and a second intra-prediction mode based on the left template region. The video coder generates first and second predictors for the current block based on the first and second intra prediction modes. The video coder encodes or decodes the current block by using the first and second predictors to reconstruct the current block.

A video coder may code a flag indicating whether or not a neural network (NN)-based intra prediction mode is enabled before coding a decoder side intra mode derivation (DIMD) flag, and code a block of video data based on whether or not the NN-based intra prediction mode is enabled.

Methods and apparatus for video coding are disclosed. One method determines a prediction direction between vertical prediction and horizontal prediction for the current block based on a template of the current block or based on decoder side intra mode derivation (DIMD) using statistics or histogram of angle field derived from the template of the current block. According to another method, the current block is partitioned into a first region and a second region according to a region split. The first region is encoded or decoded based on inter coding. The second region is encoded or decoded according to intra coding. At least a part of region-spit parameters, a part of inter coding parameters, or a part of intra coding parameters are determined based on a template of the current block or based on DIMD using statistics or histogram of angle field derived from the template of the current block.

Provided is an image decoding method performed by a decoding apparatus, the image decoding method including receiving image information including at least one of decoder-side intra mode derivation (DIMD)-related information or template-based intra mode derivation (TIMD)-related information from a bitstream, deriving an intra prediction mode of a current block on the basis of the at least one of the DIMD-related information or the TIMD-related information, generating prediction samples of the current block on the basis of the intra prediction mode, and generating reconstructed samples of the current block on the basis of the prediction samples of the current block. The image information includes matrix-based intra prediction (MIP) flag information, the DIMD-related information includes DIMD flag information indicating whether a DIMD mode is applied to the current block, the TIMD-related information includes TIMD flag information indicating whether a TIMD mode is applied to the current block, and the DIMD flag information or the TIMD flag information is parsed after the MIP flag information.

Methods and apparatus for video coding. When a current intra angular prediction mode for the current block is not in the MPM list, a mode syntax related to a current intra prediction mode for the current block is signalled or parsed depending on first information derived according to DIMD or TIMD. A final intra predictor is generated based on second information comprising the first information and the mode syntax. The current block is encoded or decoded using a final mode derived based on information comprising the syntax.

A coded video bitstream is received. The coded video bitstream includes coded information of a current block in a current picture, the coded information indicates that the current block is coded by an intra prediction using an affine intra mode (AIM) model. The affine intra mode model for applying on the current block is determined. At least a first intra angular mode for a first sample in the current block and a second intra angular mode for a second sample in the current block are determined according to the affine intra mode model, the first intra angular mode is different from the second intra angular mode. The current block is reconstructed based on the intra prediction using the affine intra mode model, the first sample is predicted based on the first intra angular mode and the second sample is predicted based on the second intra angular mode.

A method of deriving a Decoder-side Intra Mode Derivation (DIMD) predictor for respective samples of a coding unit (CU) of a picture, includes: splitting a template area adjacent to the CU into a plurality of template area regions; separately selecting no, one or more Intra Prediction Modes (IPMs) in each template area region, wherein the selection involves a selection out of the separately determined IPMs for the entire CU or for one or more regions of the CU; determining blending weights using the selected IPMs, and generating the DIMD predictor by blending at least the selected IPMs using the determined blending weights.

A method for performing template-based intra mode derivation (TIMD) with enhanced candidate intra-prediction modes is provided. A video coder determines a set of most probable modes (MPMs) for intra-coding the current block based on intra-prediction modes used to code neighboring blocks of the current block. The video coder determines a template of the current block among already-reconstructed pixels neighboring the current block. The video coder determines a set of candidate intra-prediction modes to include (i) the set of MPMs and (ii) one or more intra-prediction modes neighboring an MPM in the set of MPMs. The video coder derives an intra-prediction mode from the set of candidate intra-prediction modes based on the determined template and the set of candidate intra-prediction modes. The video coder encodes or decodes the current block by using the derived intra-prediction mode to generate an intra-prediction.

An image decoding method performed by a decoding device includes: obtaining image information including prediction-related information from a bitstream; determining whether combined inter-picture merge and intra-picture prediction (CIIP) is applied to a current block, on the basis of the prediction-related information; deriving a prediction sample of the current block on the basis of it being determined that the CIIP is applied to the current block; and generating a reconstructed sample of the current block on the basis of the prediction sample, wherein the prediction sample of the current block is derived on the basis of an intra prediction sample and an inter prediction sample, wherein the intra prediction sample is derived on the basis of an intra prediction mode, wherein the intra prediction mode is derived on the basis of a decoder side intra mode derivation (DIMD) mode or a template-based inter mode derivation (TIMD) mode.

A video coder is configured to determine a first set of transform sets and a second set of transform sets, determine, for a current block of video data coded using a non-directional intra mode, a list of intra prediction directions determined from a decoder-side intra mode derivation (DIMD) process applied to prediction block samples of the current block, determine, for the current block, a transform set from the second set of transform sets based on a second highest intra prediction direction in the list of intra prediction directions, and encode or decode the current block using a transform in the transform set.

A device may obtain a reference block associated with an inter prediction of a video block. The device may determine an intra-prediction mode associated with the video block based on one or more intra-prediction modes associated with the reference block. The device may decode or encode the video block based on the intra-prediction mode. In examples, the device may decode or encode the video block using an intra prediction and the inter prediction, and the intra prediction of the video block may be based on the intra-prediction mode. For example, combined intra-inter prediction (CIIP) may be enabled for the video block. CIIP for the video block may include the intra prediction of the video block and the inter prediction of the video block. The intra prediction of the video block may be based on the intra-prediction mode.

A video coding method using decoder-side intra mode derivation (DIMD) based on multiple histograms of gradients (HoGs) is provided. A video coder receives data to be encoded or decoded as a current block of a current picture of a video. The video coder derives a plurality of HoGs for different intra prediction angles. Different HoGs are derived based on different sets of reconstructed pixels neighboring the current block. The video coder selects a HoG from the plurality of HoGs. The video coder identifies one or more intra prediction modes based on the selected HoG. The video coder generates an intra-prediction of the current block based on the identified one or more intra prediction modes. The video coder encodes or decodes the current block by using the generated intra-prediction.

Methods and apparatuses for video decoding and video encoding and a method of processing visual media data are disclosed. The apparatus for video decoding includes processing circuitry that receives coded information indicating that a current block in a current picture is coded with a decoder-side intra mode derivation (DIMD) mode. A template of the current block includes reconstructed samples in the current picture and is adjacent to the current block. The template includes one of a left template and a top template. The processing circuitry determines a filter type from a plurality of filter types associated with the one of the left template and the top template, applies the DIMD mode to the template based on the determined filter type to determine one or more intra prediction modes for the current block, and reconstructs the current block according to the one or more intra prediction modes.

A method for decoder-side intra mode derivation (DIMD) by inheriting histogram of gradients (HoG) from neighborhood is provided. A video coder derives a current HoG for a current block by inheriting one or more HoGs from neighboring blocks in a vicinity of the current block. The inherited HoGs may include one or more augmented HoG that is derived without gradient calculation. The inherited HoGs may include one or more HoG that is re-generated for a neighboring block that already has a HoG that is stored and available for inheritance by the current block. The video coder identifies two or more intra-prediction directions based on the current HoG. The video coder encodes or decodes the current block by using the identified intra-prediction directions to generate a prediction of the current block.

The various implementations described herein include methods and systems for coding video. An example method of video decoding includes receiving a video bitstream comprising a plurality of blocks that includes a current block. The method also includes, for each neighboring block in a set of neighboring blocks of the current block, when the neighboring block is coded using a template-based intra prediction mode derivation (TIMD), populating a candidate list for the current block with an entry for the neighboring block, where at least one entry in the candidate list comprises a three-mode entry. The method further includes reconstructing the current block using an entry from the candidate list.

An image encoding / decoding method and apparatus, a recording medium storing a bitstream and a transmission method are provided. The image decoding method may comprise generating a derived intra prediction mode by performing decoder side intra mode derivation (DIMD) on a current block and storing the derived intra prediction mode. The current block is in a matrix based intra prediction (MIP) mode.

A video coder determines, based on a first indication of a decoder-side intra mode derivation (DI MD) prediction mode being enabled for coding a current block: a first histogram of gradients (HoG) based on the current block; and a second HoG based on a neighboring block of the current block. A value is determined representing a similarity between the first HoG and the second HoG. Based on comparing the value with a threshold value, a set of parameters is selected, from a first set of parameters and a second set of parameters, for the DIMD prediction mode. The coder codes the current block using a DIMD predictor generated based on the set of parameters.

Methods and systems are described for intra-prediction using template matching (TM) in video coding. The proposed methods include adaptive fusion when using template-based intra mode derivation using the most probable modes (TIMD), and fusion in intra mode prediction with template matching (Intra TMP).

A method and apparatus for video coding. According to the method for the decoder side, coded data associated with a current block to be decoded is received. A curved intra prediction model associated with a curved intra prediction mode is determined for the current block, where the curved intra prediction model is derived based on a template of the current block or based on decoder side intra mode derivation using statistics or histogram of angle field derived from the template of the current block. The template comprises at least 3 lines in a neighbouring region of the current block. The current block is decoded using one or more intra prediction mode candidates including the curved intra prediction mode.

A video bitstream including coded information of a current block in a current picture is received. The coded information indicates a plurality of candidate intra prediction modes for the current block. Two or more predictors are determined based on the plurality of candidate intra prediction modes for the current block according to a pre-defined condition. At least one of the two or more predictors is generated based on a matrix-multiplication mode of the plurality of candidate intra prediction modes such that the at least one of the two or more predictors is obtained by a matrix multiplication of a matrix of weight coefficients and neighboring reconstructed samples in a template of the current block. The current block is reconstructed based on a weighted combination of the two or more predictors.

Methods are described for template matching (TM) in video coding. The proposed methods include: the use of constrained top and left neighbors in template matching, enabling TM only in coding tree unit boundaries, using approximated reconstructed samples, a new processing pipeline for deriving decoder side intra mode derivation (DIMD) combined with template based intra mode derivation (TIMD), and using filtered pixels from the neighbors, instead of using the reconstructed pixels. Furthermore, methods are described on how template matching may be applied in combination with Intra, sub-partitioning mode, interpolation filtering in intra prediction, block partitioning, bi-prediction with coding unit-level weights, and adaptive motion vector resolution.

Systems, methods, and instrumentalities are disclosed herein for the field of video compression. Examples herein aim at improving compression efficiency compared to existing video compression systems. In examples, a video encoder may obtain a reference picture of a current picture. The reference picture may include a clean region and a dirty region divided by a boundary. The encoder may obtain a motion compensated block associated with a current block in the reference picture. The encoder may obtain, based on the motion compensated block, an associated intra-coded block. The encoder may determine intra mode propagation information for the current block based on a location of the intra-coded block relative to the boundary. The current picture may be encoded based on the intra mode propagation information.

Methods for video decoding and encoding, apparatuses and non-transitory computer-readable storage media thereof are provided. In one method for video decoding, a decoder may obtain a first and a second block, where the first block is coded with an Intra Block Copy (IBC) mode or an intra Template Matching Prediction (TMP) mode, and the second block is coded with the intra TMP mode or the IBC mode. Additionally, the decoder may obtain a boundary strength for a deblocking filter by applying a predefined criterion in one of an intra mode or an inter mode. Further, the decoder may apply, and based on the boundary strength, the deblocking filter on the first block and the second block.

Intra prediction modes are determined for entry in most probable mode lists for encoding in video encoders and decoding in video decoders. In at least one embodiment, coding modes are derived to determine reference samples to use from inter coded neighboring blocks. In one embodiment, up to five neighboring blocks are used. The reference samples are used in an intra prediction mode to determined prediction samples. The reference samples are used for prediction in encoding or decoding. In at least one embodiment, one of several motion models can be used to extract the intra motion mode. The intra motion modes are used to fill a most probable mode list. The motion model, intra mode, or reference frame can be signaled from an encoder to a decoder.

A method of deriving a Decoder-side Intra Mode Derivation, DIMD, predictor for respective samples of a coding unit, CU, of a picture includes selecting one or more Intra Prediction Modes, IPMs, in a template area adjacent to the CU, determining blending weights for blending at least the one or more selected IPMs, and generating the DIMD predictor by blending the one or more selected IPMs using the determined blending weights for the CU so that the blending varies over the CU.

In order to better predictively encode pixels of an image block of a video, a method of predicting a block of pixel colors of an image is proposed, comprising: determining a template-based intra mode to derive a prediction applicable to the block; determining a plurality of intra prediction modes, and determining respective costs for the plurality of intra prediction modes; determining that a first TIMD mode is a first intra prediction mode of the plurality of intra prediction modes having the lowest cost of the respective costs, and a second TIMD mode is a second intra prediction mode of the plurality of intra prediction modes having a penultimate cost of the respective costs; determining a third TIMD mode as a non-angular intra prediction mode; performing a verification with respect to the third TIMD mode being different from the first TIMD mode and the third TIMD mode being different from the second TIMD mode; forming a final TIMD mode based on the verification as true, the final TIMD mode comprising a linear combination of the first TIMD mode, the second TIMD mode, and the third TIMD mode; and forming a prediction of the block based on a template of the block and the final TIMD mode.